Description: RCRA contains no general statutory or regulatory definition of a monofill. RCRA Section 3004(o)(3) states that the minimum technological requirements (MTR) may be waived by the Administrator for any monofill under certain conditions. The unit must have at least one liner with no evidence of leakage, be located more than one-quarter mile from an underground source of drinking, and be in compliance with the applicable groundwater monitoring requirements (Section 3005(j)).

Description: The Agency allows the appropriate use of fate and transport modeling to demonstrate, under clean closure, that materials contaminated with waste that are not removed do not present unacceptable risks. The use of modeling to make demonstration does not affect the requirements for removal of all wastes (SEE ALSO: RPC# 9/24/96-01). EPA's commitment to public participation is the same whether corrective action is implemented in the context of a RCRA permit or an enforcement order. EPA expects that non-RCRA cleanups will provide an appropriate level of public participation. The public has an opportunity to review and comment on whether it is appropriate for the Agency to defer RCRA corrective action to a non-RCRA program in certain instances.

Description: Owners and operators of hazardous waste surface impoundments, landfills, and land treatment units can delay the closure timetable beyond the 90-day period and allow the units to accept nonhazardous waste, if the units meet the conditions of Sections 264.113(d)/265.113(d). Owners or operators of tanks, containers, waste piles, and incinerators are not allowed to delay closure. These units must comply with all applicable closure standards before being able to accept nonhazardous waste.

Description: Bare concrete can serve as a container storage pad for secondary containment. No regulatory definition of sufficiently impervious is available. Bare concrete is insufficiently impervious for primary containment when in continuous contact with waste (e.g., in surface impoundments or waste piles). Secondary containment regulations are performance standards that allow for the use of materials other than concrete or asphalt.

Description: All landfills, surface impoundments, waste piles, and land treatment units that received waste after July 26, 1982 are subject to post-closure permitting and Part 264 Subpart F standards unless the owner demonstrates that closure under the previous Part 265 standards met Part 264 closure by removal standards (SUPERSEDED: See 63 FR 56711; October 22, 1998). Under RCRA 3005(i), EPA has the authority to revisit interim status clean closures and require post-closure permits if closure does not meet closure by removal standards of Part 264. In order to demonstrate clean closure, an owner generally should remove “hot spots” of contamination.

Description: Waste cannot be disposed of unless treated to land disposal restrictions (LDR) treatment standards, disposed in no-migration unit, or subject to exemption or variance from treatment standards. D001 ignitable waste must be treated to treatment standard before disposal. There are special requirements for ignitable wastes placed in a surface impoundment, landfill, waste pile, and land treatment unit.

Description: Discusses an automatic waste feed shut-off design for munitions deactivation (popping) furnaces and fugitive emissions control from popping furnaces. Pits used for dewatering and open burning are surface impoundments, not miscellaneous units. EPA can use omnibus provisions to impose additional controls on open burning in surface impoundments. Waste explosives that do not have the potential to detonate cannot be destroyed in open burning/open detonation (OB/OD) units. Solvents contaminated with explosives that have the potential to detonate can be open burned. Because open burning/open detonation (OB/OD) of waste explosives is treatment, not disposal, the land disposal restrictions (LDR) do not apply. Treatment residues may be subject to LDR. Clarifies when the disposal of explosives requires a permit and when unused explosives become wastes (SEE ALSO: 62 FR 6622; 2/12/97). Burning commercial fuel in fire training exercises is not regulated under RCRA. Discusses methods of determining soil background levels for the clean closure of surface impoundments and waste piles, circumstances in which the unit type can be redesignated during interim status, cleanup standards for corrective action, compliance points for soil and groundwater cleanup, timing of corrective action cleanup activities and site monitoring, termination of groundwater corrective action, the use of institutional controls, the use of trial burn data from one facility at other incinerators, the evaluation of trial burn plans for popping furnaces, and the use of in-place hydraulic conductivity testing during liner installation for surface impoundments and landfills. A landfill’s clay layer component of the final cover must be completely below the average frost depth. Addresses the use of natural material (calcium carbonate) and cement kiln dust in waste stabilization, the use of the RCRA corrective action plan (CAP) in HSWA permit preparation, the use of the 261.4(f)(2) authority to implement Subpart X standards in RCRA authorized states, and the permitting deadlines for Subpart X facilities.

Description: The owner of a surface impoundment or waste pile that received hazardous waste after 7/26/82 and clean closed per 265 standards must submit a post-closure permit application within 6 months of an EPA request (SUPERSEDED: See 63 FR 56711; 10/22/98). An owner of a waste pile clean closed per 265 should submit an equivalency demonstration before a Part B permit application is requested. Submitting an equivalency demonstration does not exempt the owner from having to submit a post-closure permit application.

Description: Clean closure levels for surface impoundments, waste piles, and land treatment units must be based on EPA-recommended exposure levels or factors that have undergone peer review by EPA. Where no health-based levels exist, clean closure levels are based on background or exposure levels submitted by the owner based on toxicity data. Includes recommendations for clean closure levels for lead and cadmium. Lead background levels should be established by taking soil samples at an uncontaminated area of the facility or by using published literature data on lead levels in similar soils (SUPERSEDED: see RPC# 5/7/90-01).

Description: Under 270.1(c), owners of interim status surface impoundments and waste piles who clean closed under the old Part 265 closure standards may demonstrate equivalency with the 264 closure standards. Discusses the contents of the demonstration equivalency and the procedures for submittal. If an attempt at a closure equivalency demonstration does not meet the 264 standards, the owner must submit a Part B permit application. Addresses the acceptability of specific information supporting equivalency demonstrations. An owner of an interim status landfill where waste was removed at closure can reclassify it as a waste pile and demonstrate clean closure equivalency, or the owner may request a shortened post-closure care period (SEE ALSO: 63 FR 56711; 10/22/98).

Description: VERIFIED REFERENCE DOSES (RFDS) AND Carcinogenic Potency Factors (CPFs) can be used to set soil cleanup levels during clean closures of surface impoundments, waste piles, and land treatment units. Where no EPA-recommended health-based limit exists for a contaminant, a soil cleanup level may be based on background levels or by data developed by the owner to support a health-based limit. If the cleanup level cannot be established, then clean closure cannot be achieved and the unit (i.e. surface impoundment, waste pile, or land treatment unit) must close as a landfill. Provides guidance for determining the background levels for lead in soil for clean closures of surface impoundments, waste piles, and land treatment units. Discusses how to determine background levels of lead in soil.

Description: Certain instances of non-compliance do not require reporting under 270.30(l)(10). These are limited to minor recordkeeping, reporting, and similar oversights that are immediately corrected. 270.30 reporting requirements are limited to non-compliance with permit conditions (SEE ALSO: 60 FR 66706; 12/22/95).

Description: Surface impoundments, waste piles, landfills, and land treatment units which received waste after 7/26/82 or certified closure after 1/26/83 must either have post-closure permits or demonstrate that clean closure was equivalent to Part 264 closure (270.1(c)) (SEE ALSO: 63 FR 56711; 10/22/98). Post-closure permits for these units would include Part 264 groundwater monitoring, unsaturated zone monitoring, corrective action and post-closure care.

Description: Discusses the regulatory status of a coal tar decanter sludge waste pile. K087 stored before recycling in coke or coal tar production is not exempt under 261.6(a)(3)(vii) (SUPERSEDED: See 56 FR 7203; 2/21/91, 261.4(a)(10), and 261.4(a)(12)).

Description: EPA may extend the time allowed for the closure of a surface impoundment to allow groundwater corrective action so that the owner can achieve clean closure. Units closing by removal under Part 265 (e.g. surface impoundments, waste piles, and land treatment units) must obtain post-closure permits unless the owner demonstrates equivalence with 264.228, 264.280(e), or 264.258 closure by decontamination standards (SEE ALSO: 63 FR 56711; 10/22/98). The owner of an interim status landfill that has closed by removal and has not triggered groundwater assessment does not have to monitor groundwater for the full list of Appendix VIII or IX constituents. Groundwater evaluation conducted as part of the 265 clean-closure demonstration should establish constituents that could reasonably be expected to exist at the impoundment. A surface impoundment that has triggered groundwater assessment may not be able to clean close.

Description: Variances from the minimum technological requirements (MTR) may be obtained if an alternate system can prevent the migration of any hazardous constituents into the groundwater. The term groundwater is not limited to only groundwater beyond the waste management area (surface impoundment, waste pile, landfill).

Description: The 261.6(a)(3)(v) exemption is only for coke and coal tar products recycled from coal tar decanter sludge (K087), not for K087 stored in a waste pile before recycling. K087 used to produce coke is not an exempt use or reuse because it is used for a fuel (SUPERSEDED: See 56 FR 7203, 2/21/91; and 57 FR 27880, 6/22/92; and 261.4(a)(10), and 261.4(a)(12)).

Description: Describes a tank as a unit that contains materials and a waste pile as a noncontainerized accumulation of solid, non-flowing hazardous waste. Discusses approaches to address the overlap of the definitions of tank and waste pile and the applicability to 3 and 4-sided floored structures.

Description: A native soil foundation does not constitute a liner for the purposes of the 3005(j)(2) waiver. A 264.282 compatibility demonstration applies to both hazardous and nonhazardous waste. Addresses HSWA waste minimization requirements (3002(b)) and the application of sludge to land treatment units. The identification of principal hazardous constituents for land treated wastes must include all constituents that may enter the waste stream. A land treatment unit performance evaluation must include the unit’s ability to treat and degrade organic constituents, as well as its ability to immobilize heavy metals. Provides guidance on the frequency of soil pore liquid sampling at land treatment units (unsaturated zone monitoring) and guidance on screening groundwater monitoring wells. QA/QC methodology at a land treatment unit should include verification of the organic constituent analysis by gas chromatography/mass spectroscopy (GC/MS). Includes guidance on the content of construction quality assurance plans. A person who conducts quality assurance measures for surface impoundments, waste piles, and landfills should be independent of the construction contractor. Discusses the use of Method 9090 for compatibility testing of liner materials with waste or leachate. All man-made materials that contact waste or leachate should be subjected to the immersion test portion of 9090. A sample of waste or leachate used in compatibility testing must be representative of the actual waste or leachate managed in the surface impoundment, waste pile, or landfill. A concrete pad cannot be equivalent protection. If the design slope of a final landfill cover exceeds 3-5%, the applicant must demonstrate that soil erosion will not be excessive and may need to perform a slope stability analysis. Waste and soil settlement must be included in calculations for the final landfill cover design to be substituted for a waste pile liner as equivalent protection under 3015(a). A flexible membrane liner should not be used in a final cover when the landfill is unusually deep and slopes are steep. Clean, not contaminated, soil should be used for the final cover. A leachate collection system design should be based on realistic infiltration rates. Geogrid and geotextile materials used in place of conventional drainage materials for a landfill must have an equivalent drainage capacity of a one-foot layer of compacted sand. Berms constructed of manufactured slag should not contain hazardous constituents. For landfills, the use of a composite primary liner below the primary synthetic liner is allowable. An owner of a land treatment unit who cannot establish vegetative cover may use an alternate closure procedure. A facility cannot extend closure in order to receive nonhazardous waste (SUPERSEDED: see current 264.113(d)). Addresses the role of the Agency for Toxic Substances and Disease Registry (ATSDR) in exposure information and evaluation. The review of Exposure Information Reports should be coordinated with ongoing RCRA Facility Assessments.

Description: Spent refractory bricks as ingredients in new bricks are not solid waste unless speculatively accumulated. Processing (briquetting, crushing, repackaging) not recovering material values is not reclamation. If direct reuse is exempt, the spent material or by-product status is irrelevant. Waste pile representative sampling should entail dividing the waste pile into quadrants with each quadrant sampled using a two-dimensional grid and a random vertical core sample.

Description: HDPE (high density polyethylene) is not a universal material for a liner and leachate collection system for surface impoundments, waste piles and landfills. Different HDPE material varies in physical and chemical properties. A liner and leachate collection system must be chemically resistant to waste in a landfill. This memo provides suggestions for testing landfill components.

Description: Waste piles, since they are land disposal units, should have had permit applications issued or denied by November 1988 (HSWA 3005(c)(2(A)(i)). Discusses priorities for issuing post-closure permits. EPA can apply 3008(h) or 3004(u) (through post-closure permits) at land disposal units with likely or actual releases (SEE ALSO: 63 FR 56711; 10/22/98).

Description: Groundwater quality is an integral part of closure for surface impoundments and waste piles. Post-closure permits, 3008(h) corrective action orders, and 3004(u) corrective action can be used to supplement interim status regulations. The approval and completion of closure by removal does not preclude the use of 3008(h) or 3004(u). A summary of 3005(i), 3004(u), and 3008(h) authorities as they pertain to surface impoundments and waste piles.

Description: The 3004(o) minimum technological requirements apply to landfills and surface impoundments, but not to waste piles. RCRA 3015(a) imposes liner and leachate collection requirements on new interim status waste piles, lateral expansions, and replacements. Expansions of interim status waste piles must be lined if they exceed the boundaries of the existing unit (3015(a)).

Description: Precipitation run-off (PRO) is not presumed to be a hazardous waste. Mixtures of hazardous waste leachate and PRO are hazardous. PRO from active portions of landfills/waste piles is presumed to be hazardous due to mixing with the leachate. PRO from closed portions of landfills is presumed to be nonhazardous. PRO from land-treatment units is presumed to be nonhazardous. PRO is a liquid which flows over and quickly off the land. PRO is excluded from the derived-from rule. PRO is hazardous if it exhibits a characteristic or is mixed with a hazardous waste. Leachate refers to liquid that has made significant contact with hazardous waste. Leachate from a characteristic waste is presumed hazardous until it is shown not to be hazardous. Under the mixture rule, waste mixtures containing a characteristic waste are like other solid waste and are hazardous if they exhibit a characteristic.

Description: If waste is dumped on the ground outside of a land treatment unit, the area should be regulated as a waste pile or landfill. EPA does not recommend dumping and spreading as an adequate land application procedure (SEE ALSO: 61 FR 18779; 4/29/96).

Description: An interim status waste pile leaking hazardous leachate into the ground is out of compliance. The owner or operator can take remedial action or modify their Part A permit application, reclassifying the waste pile as a land treatment unit or landfill, for which groundwater monitoring would be required under changes during interim status.